HANFORD | COVER STORY
Left: The Plutonium Finishing Plant’s ventilation stack toppled to the ground in July 2017 Photo credit: US DOE
using a conveyance system connected to pipes, called “risers” that stick out of the top of the structures.
Dealing with sludge In 2018 CHPRC began removing highly radioactive sludge from temporary storage in containers located inside the 105-K West Basin near the Columbia River — a water filled pool.
The sludge is a mixture of tiny fuel corrosion particles,
metal fragments, and accumulated dirt produced as irradiated fuel rods stored in the 105-K West Basin began to deteriorate. There was 35 cubic yards of sludge in the basin. The sludge was transferred to a more secure long-term
storage location near the centre of the site with secondary containment basins, leak detectors, and vents to keep the containers in a safe configuration. Workers spent years developing the sludge removal system. “The sludge is some of the most hazardous material at
Hanford, so moving it away from the river to safe storage in a robust engineered facility in the centre of the site significantly reduces risk,” said Doug Shoop, manager of DOE’s Richland Operations Office. The sludge will remain at T Plant until final disposition decisions are made
Changing the site skyline In 2017 workers removed a landmark from the Hanford Site skyline, with the demolition of the ventilation stack at the PFP. The 200-foot-high exhaust stack serviced the PFP for 68 years. The subcontractor, Controlled Demolition, Inc, used a small amount of explosives to weaken the stack, allowing gravity to bring it to the ground. The same technique had been used to demolish similar structures at Hanford and was considered safer and more efficient than having workers, at elevated levels, use cranes and other equipment to demolish the tall structure.
Contaminated portions of the facility’s ventilation system
had already been removed and crews spent six months planning for the demolition. With the ventilation building and stack removed, demolition was complete on two of the four main processing buildings that made up PFP. “The stack demolition is the result of years of preparation to clean out the contaminated facility to the point where the ventilation system isn’t needed and can be demolished,” said Tom Teynor, project director for PFP demolition at the Department of Energy (DOE) Richland Operations Office. “Removing the stack is not only historic, but it allows workers in heavy equipment to more easily access and demolish the remaining portions of the facility.” The start of 2020 saw another change in the skyline
when crews finished demolishing the PFP’s main processing facility. It had produced two-thirds of the nation’s Cold War plutonium and stood for 40 years of operations and 20 years of cleanout and demolition preparation. The main processing facility was nicknamed “Z-Plant,”
because it was the last stop of plutonium production at Hanford. It operated from 1949 to 1989 and contained two processing lines where workers working through gloveboxes would create hockey puck-sized plutonium “buttons” for shipment to weapons-manufacturing facilities. Plutonium production left gloveboxes and other pieces of plutonium processing equipment highly contaminated. Decades of demolition preparations included
decontaminating and removing about 200 pieces of plutonium processing equipment like glove boxes, 1.5 miles of ventilation piping, contaminated process lines, asbestos and other hazards. In some instances, such as cutting and removing two highly contaminated glove boxes, workers performed some of the most hazardous work anywhere across the DOE complex. Demolition has been under way over the last five years, starting with connected buildings: an americium recovery U
Left: Sludge removal from 105-K West Basin Photo credit: US DOE
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